Absorbant and reflecting biocompatible dyes for highly accurate medical implants

Abstract

A light-polymerizable composition for additive manufacturing of resorbable scaffolds and implants comprising a biocompatible resin. The biocompatible resin includes a combination of photo-initiators or a dye-initiator package tailored to manufacture implants with the desired physical and chemical properties. A dye or other constituent controls between layer (z) resolution of the manufactured part built in an additive manufacturing device. A light absorber or other constituent controls within layer (x-y) resolution of the manufactured part.

Description

FEDERAL FUNDING NOTICE[0001]This invention was made with government support under grant numbers R01-DE013740 and R01-AR061460 awarded by the National Institutes of Health (NIH). The government has certain rights in the invention.BACKGROUND[0002]Tissue engineering is an attempt to regenerate a defect in tissue that is larger than the unaided body can regenerate on its own. In most cases tissue engineering requires technology for the creation of three components: implants (often referred to as scaffolds), cells and growth factors. Tissue regeneration not only requires the infusion of cells specific to the function of the organ but also vasculature and often connective tissue. Growth factors can aid in the performance of concentrated tissue precursor cells or the recruitment of reparative host tissue. Implants or scaffolds are often required to provide guidance to stem cells and / or invading host tissue, vasculature and connective tissue. Implants may be designed to match a defect in a ...

AI Technical Summary

Benefits of technology

The patent text describes a composition for 3D printing resorbable scaffolds and implants that can be controlled to have specific resolutions. The composition includes a dye, a photo-initiator, and a light absorber. The dye controls the resolution of the manufactured part, while the photo-initiator and light absorber control the resolution within the plane of the manufactured part. The use of specific dyes and photo-initiators can improve the strength and accuracy of the printed parts. The technical effect of this composition is to provide a more precise and reliable method for manufacturing resorbable scaffolds and implants using 3D printing technology.

Problems solved by technology

If the walls between porous spaces of the implant or scaffold are too thick they may not resorb, and thereby become a barrier to remodeling.

If the materials degrade, their byproducts need to be non-toxic and easily metabolized so that they do not prevent tissue regeneration or remodeling.

However, concerns may arise as to the resorbability of the crystals in the host's body.

For example, accurate rendering makes it more likely that complex internal pore structures such as those described above and other can be created.

However, post-curing handling of low molecular weight scaffolds or implants could be problematic and thus the ideal rendering method would minimize any post-curing handling necessary.

While stereolithographic rendering of implants and scaffolds has been demonstrated, limitations in the commercially available devices has thus far resulted in relatively low accuracy levels.

For example, accuracy and resolution of conventional stereolithographic rendering devices may not allow the devices to produce scaffold or implant surface features such as pores and pore openings at the low end of the optimum geometry scale.

While conventional stereolithographic rendering devices may be able to produce orthogonally oriented pore structures in implants and scaffolds, they may not be able to provide sufficient resolution to produce obliquely oriented pores.

Moreover, stereolithographic rendering may also have various other limitations in the context of manufacturing of implants or scaffolds.

The drawing speed is typically not fast enough to simultaneously draw all pixels in the layer, which may make it difficult to control pixel to pixel crosslinking within the layer and / or over-curing or stitching between layers as the implant or scaffold is rendered.

Also, conventional stereolithography devices may not provide a way to modulate the amount of energy at one spot versus another within a layer to, for example, control the depth of polymerization and level or strength of over-curing.

Furthermore, dyes that are effective against ultraviolet transmission and USP grade are even harder to come by.

However, in its effectiveness, there is an inevitable downside, while titanium dioxide is a strong ultraviolet absorber, it also has strong scattering properties, which leads to inadvertent curing, thereby decreasing resolution in the xy-plane and potentially z-plane as well.

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